could well be the origin and date that Ross suggests. Regarding 'matching Nos.' - can say that I have modern (post 1960 bottles) from Stuart and R/Brierley that have this feature - but seems they are found only to top quality pieces - ost of the 'also rans' are without Nos.
Never quite sure when this habit of numbering began - certainly you don't see them on Regency pieces nor, I don't think, on early Victorian decanters - I get the feeling they started around c. 1860, but not sure, and very interested to hear what others think.
